The present invention relates to hand-free operator permitting a user to make a dial externally, and more particularly to an external dialing device adaptable for use on all kinds of cellular phones. It can advance driving safety and facility of using cellular phone.
Generally, it is the most annoying thing to common people to locate phone numbers when using a phone. So, to help people make dials ready and fast, conventional dialing devices have been commercialized on markets. Thereby people can make dials by inputting simplified codes into a dialing device which causes the dialing device to pick up a telephone number stored in advance in a memory unit thereof for dialing operation. The only thing a person using the prior dialing device is to bring such a dialing device close to a common telephone receiver so that DTMF sound produced by the dialing device can be received by a phone receiver. That will do it. It is simple and facilitating However, in nowadays, cellular phones becomes so popular in modern societies, the conventional dialing devices can not be applied thereto for the following reasons:
1. In the cellular phones, there is no DTMF decoding unit provided, so the DTMF sound can not activate a cellular phone to make a dial. PA0 2. Each kind of cellular phone adopts its own communication protocol, for instance the codes for instruction wordings SEND, END, 0,1 . . . 9 are different. So, a dialing device can not be used at all.
The inventor has noticed the problem of conventional dialing devices being not able to be applied to cellular phones. He worked hard to come up with a dialing device equipped with a dial processing unit in a hand-free operator so that it can be operated in cooperation with a dialing device to make a direct dial on a cellular phone possible.